ownCloud is prone to an arbitrary-code execution vulnerability, multiple HTML-injection vulnerabilities and multiple cross-site scripting vulnerabilities because it fails to properly sanitize user-supplied input. Successful exploits will allow attacker-supplied HTML and script code to run in the context of the affected browser, potentially allowing the attacker to steal cookie-based authentication credentials or control how the site is rendered to the user and to execute arbitrary code in the context of the web server. Other attacks are also possible.